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Rick, General Contractor
Category: Home Improvement
Satisfied Customers: 19056
Experience:  Licensed construction supervisor with 35+ yrs. experience.
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Need Help Removing mildew on Wood Siding & Pillars

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We've accumulated some mildew on our wood siding and pillars. Someone told me to use a Wet & Forget ( product by but it has to be applied with extreme care for plants, people, pets and ponds. Others have said to just use diluted bleach. Please let me know the easiest and safest to remove this mildew from our siding and pillars. Thanks!




Rick :

Welcome, my name is XXXXX XXXXX I will do my best to help you with your issue.

It really depends on the area surrounding what you need to clean. Wet & Forget is also helps prevents mold from coming back. It's this part of the product that's troublesome for anything organic. So if you're concerned about any of the things you mention becoming contaminated with any run off then a simple bleach solution will also work

Rick :

But it may take a little scrubbing to get rid of all the mildew. Bleach will kill the mold or mildew but won't do much to prevent its return. Once your done a thorough rinsing should sufficiently dilute the bleach so it has no harmful affects to the surrounding area


Can you switch out of the chat feature. I have troubles with this and prefer to send messages back and forth. Thanks!

Can you see my initial post? do you have any more questions?
Customer: replied 3 years ago.

I responded but it didn't show up here. Please let me know if you can see this response, and then I'll repost my follow-up question to the best of my ability. Thanks!


Yes I can see your latest response
Customer: replied 3 years ago.

OK, I'm not sure what happened there. Anyway, my follow-up questions related to the ratio of water to bleach that you would recommend. Also, should I use a sprayer, bucket with brush or both to apply the solution? Our gutters run down to our pond. Should I avoid letting the bleach/water solution running down our gutters? I could probably plug the drains with a towel to catch any potential runoff. Would the Wet & Forget solution be better in areas that don't run down to our gutters or plants? Thanks!

1 cup of bleach to a gallon of water will do the job and yes it would be a good idea to block the bleach runoff from getting into the pond. Wet & Forget would be an easier option than bleach since you'll need to do at least some scrubbing with the bleach solution. A brush with a long handle (broom length) works best. Judging from the pictures you may need to paint after you clean the mildew no matter what you do. I doubt anything will make the post you pictured look bright white again. If you paint you might want to add a mildewcide to the paint to inhibit mildew growth in the future. Most paint stores carry mildewcide additives.
Customer: replied 3 years ago.

So if I'm going to paint the pillars anyway, I should just use bleach/water to get it clean and then repaint with the mildewcide additive, right? The same would apply to the siding if I'm going to paint it. But if I just want to clean it for now, the Wet & Forget product would be a more effective way to fix the siding problem. I just need to be careful with the runoff for Wet & Forget. Is it safe to assume that once Wet & Forget dries, then the runoff is no longer a problem? Or once it gets wet after being dry, then it will potentially be a runoff issue. Please let me know. Thanks!

That's the idea. If you're going to paint (with mildewcide) then just bleach is fine. I'm skeptical that even Wet & Forget will make it look real good. Once the Wet & Forget dries the runoff should no longer be a concern.

Customer: replied 3 years ago.

Last follow-up...if I use Wet & Forget and don't think it did a good job, is it just a matter of reapplying it again after the manufacturer's recommended amount of time? Or could I use the bleach and water solution and then repaint? Again, the bleach and water solution would be tried after Wet & Forget was given a chance to work (weeks or months).

You shouldn't mix the 2 products. If Wet & Forget doesn't clean it as much as you would like then painting is your only option. There's no way to tell which (if any) will get the surface as clean as you want. I wouldn't wait more than a month or so to paint if you use bleach. If you use Wet & Forget you could wait up to a year to repaint without have to bleach/clean it again
Customer: replied 3 years ago.

Are you saying if I use Wet & Forget now on the siding, then in a year from now my only option is to paint and not try bleach/water? Please clarify how long after Wet & Forget that I could try the bleach/water solution. Thanks!

You could bleach the Wet & forget area a few months after the initial application. What I was saying is there should be no need to bleach the Wet & Forget area for up to a year.
Customer: replied 3 years ago.

Thanks! I may try the Wet & Forget in certain spots that would be tough to bleach. The manufacturer says that I can reapply Wet & Forget up to 6 times per year at least 1-2 months apart. If it doesn't work after the second application (assuming I give it time to see results), then I will wait until next year and bleach those areas and then paint with a mildewcide additive. Does that sound like a plan. I'll rate after your response.

Yes it sounds like your approach is a good one.
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